Closed-door meetings conducted by the San Diego County Water Authority deprive the public of its right to monitor the agency and must be opened up to ratepayers and others, according to a lawsuit filed Monday in San Diego County Superior Court. The suit, brought by public-interest attorney Cory Briggs, demands an end to private, unnoticed and unrecorded gatherings long held by the agency’s appointed delegates to the Metropolitan Water District of Southern California, or MWD, a regional agency based in Los Angeles.